Dislocation Patterns Research Articles

Revealing the City Influence and Its Pattern Using Web Search Data: A New Perspective Through Attention Flow

City influence is a critical topic in regional studies, reflecting how cities draw attention and exert impact in various domains. Understanding city influence is essential for fostering sustainable urban growth. However, existing studies have failed to fully explore the characteristics of city influence reflected by collective behaviors from a bottom-up perspective. This study investigates how individual search behaviors mirror the attention cities attract, providing insights into their perceived influence. An “attention flow” model is developed to differentiate between cities that draw significant interest and those that show a strong preference for these influential hubs. This research focuses on cities in China, analyzing the spatial patterns and factors that affect city influence using spatial statistical methods. The results show that 69% of the cities that exhibit a strong preference are geographically closer to the more influential cities, emphasizing the role of geographical proximity in shaping urban influence in the digital age. Additionally, the study reveals patterns of power dislocation, partnership, and siphoning between cities. A consistent relationship is identified between influential cities and their more connected cities, particularly where administrative hubs tend to attract nearby cities focused on science and education. This research deepens our understanding of how city influence is shaped by digital behaviors and spatial relationships, providing insights for policymakers to foster balanced regional development and enhance inter-city cooperation.

Epitaxial Growth of Phosphorene on Cu Substrate: The Essential Role of Interface Strain

AbstractTwo‐dimensional (2D) material epitaxially grown on a metal substrate with precise lattice registry and strong bonding can result in substantial strain within both the 2D layer and the metal surface. In turn, the strain energy has a pronounced influence on the morphology and physical properties of epitaxial films. Here, through a comprehensive approach by combining scanning tunneling microscopy and atomistic simulations, it is demonstrated that monolayer ultraflat blue phosphorene (blueP) and the topmost Cu(111) layer are in the perfect atomic registry. This Cu layer undergoes significant compressive strain, giving rise to a semi‐coherent interface between the blueP‐attached Cu layer and the underlying Cu layers. Straight and spiral dislocation patterns are observed due to strain relief, which strongly depends on the thermal annealing temperature. Dislocation lines intersect to form periodic nodes that can adopt multiple atomic arrangements correlated to the dislocation patterns. Stone‐Wales defects are distinctly imaged within the blueP layer, exhibiting periodic corrugations along the dislocation lines due to the presence of interface strain. This work underscores the potential of epitaxial layers with strong interfacial interactions as promising model systems for exploring dislocation theory and the implication for material functionality engineered by strain.

Hydrostatic pressure-mediated grain boundary smoothing and plastic deformability in high-entropy alloys

In the presence of intrinsic lattice distortion and local concentration waves, high-entropy alloys (HEAs) possess unique microstructures, deformation patterns of dislocations and grain boundaries (GBs), and superior mechanical properties. In contrast to traditional crystalline metals, GBs in HEAs have been revealed to exhibit spontaneous roughening behavior, which reduces their migration ability and weakens the plastic deformability of HEAs. In addition, hydrostatic pressure (HP) treatment can modify the microstructure and deformability of GBs in HEAs, leading to enhanced strength and ductility in HEAs. In the present work, we aim to investigate the effect of HP on GB structural evolution in HEAs and reveal the HP-induced enhancement of plastic deformability via molecular dynamics (MD) simulations. Using a FeNiCrCoCu alloy as an example, we have demonstrated that the initially rough GBs in the HEA samples undergo a smoothing mechanism under the application of HP. The GB smoothing mechanism depends not only on the initial GB misorientation and microstructure, but also on temperature and GB segregation. For the <110>(113) GB, the GB roughness is featured by individual GB segments connected by atomic-scale disconnections. Under HP, the disconnections glide along the GB plane and annihilate with neighboring disconnections, reducing the roughness of the GB. For <110>(112), <110>(114), <110>(116) and <110>(223) GBs, atomic rearrangements take place in local GB segments under HP, resulting in structural adjustment and GB smoothing. These HP-induced GB smoothing mechanisms can increase the plastic deformability of GBs under shear loading. Our findings deepen the understanding of GB plasticity in HEAs and provide insights into GB engineering through HP treatment.

Dislocation Evolution in Cyclic-Loaded Cu Nanopillars with Different Configurations.

Small-sized metals generally exhibit unusual deformation responses subjected to cyclic loading, since their limited volume cannot effectively accommodate micro-sized dislocation patterns typically found in their bulk counterparts. Here, the cyclic behaviors in Cu nanopillars with different configurations are investigated using in situ transmission electron microscopy fatigue test. Dislocation tangles formed in single- and twinned-crystal nanopillars as a result of cycling-induced operations of multiple slip systems and further unpinning and absorption of pinned dislocations. While, nanopillars configured with low-angle grain boundary (LAGB) underwent the degradation and eventual decomposition of the LAGB due to the cycling-induced emission of grain boundarydislocations, which resulted in high-density mobile dislocations to withstand the cyclic loading. These findings contribute to a systematic and comprehensive understanding of the micro-mechanics of dislocation-related phenomena in the cyclic response of nanoscale metals.

Iatrogenic Irreducible Pediatric Salter-Harris II Middle Phalanx Base Fracture With Dorsal Dislocation of the Proximal Interphalangeal Joint: A Case Report.

Pediatric phalangeal Salter-Harris (SH)-type fracture dislocations are rare injuries that often require open reduction and stabilization. We present a case of a 14-year-old male who sustained an iatrogenic irreducible SH II dorsal fracture dislocation of the small-finger proximal interphalangeal joint (PIPJ) after an attempted closed reduction of a small-finger PIPJ dislocation by a community emergency medicine physician. Following the reduction attempt, the epiphysis was noted on radiographs to be rotated approximately 90° with persistent dorsal dislocation and an associated SH II fracture of the base of the middle phalanx. The patient was sent to our trauma center for further evaluation by our on-call hand surgeon and required open reduction and pinning of the fracture dislocation. To our knowledge, this pattern of iatrogenic PIPJ fracture dislocation has not been previously described in the literature. We outline the case presentation, treatment method, and learning points for both the on-call hand surgeon as well as the community emergency medicine physicians in this report.

Comparison on Hysteresis Loops and Dislocation Configurations in Fatigued Face-Centered Cubic Single Crystals

The aggregation and evolution of dislocations form different configurations, which are the preferred locations for fatigue crack initiation. To analyze the spatial distribution of the same dislocation configuration and the resulting configuration morphologies on different observation planes, several typical hysteresis loops and dislocation configurations in fatigued face-centered cubic single crystals with various orientations were compared. The crystal orientations of these specimens were determined by the electron back-scattering diffraction technique in a Cambridge S360 Scanning Electron Microscope. It is well known that dislocation ladder and wall structures, as well as patch and vein structures, are distributed on their respective observation planes, (12¯1) and (111). These correspond to the point defect direction and line defect direction of dislocations, respectively. Therefore, the wall structures on the (12¯1) and (111) planes consist of point defects and line defects, which can be defined as point walls and line walls, respectively. Furthermore, the walls on the (12¯1) plane consist of Persistent Slip Band ladders connected with each other, corresponding to the formation of deformation bands. The evolution of dislocation patterns follows a process from patch to ladder and from vein to wall. The formation of labyrinths and dislocation cells originates from the activation of different secondary slip systems. In one word, it can help us better understand the physical nature of metal fatigue and failure by studying the distribution and evolution of different configurations.

Clarifying the relation between the marrow contusion pattern around the knee and the types of concomitant intra-articular soft tissue injuries

BackgroundAcute knee injuries represent a prevalent cause of morbidity among athletes and, if overlooked, could potentially lead to the development of chronic functional limitations. This study aimed to identify marrow contusion patterns around the knee and find the relation between each pattern and the intra- and extra-articular soft tissue injuries. This was a retrospective cross-sectional study carried out on 109 patients who presented to the hospital where the study was held with recent knee joint injury, for which magnetic resonance imaging was requested from January 2017 to January 2019.ResultsThe entire patient population under investigation had a mean age of 30.2 ± 9.7 years. Regarding gender distribution, the study comprised 90 males (82.6%) and 19 females (17.4%). Regarding bone marrow contusion patterns in all studied patients, it was pivot shift in 58 patients (53.2%), clip injury in 11 patients (10.1%), dashboard injury in 7 patients (6.4%), hyperextension injury in 3 patients (2.8%), lateral patellar dislocation in 15 patients (13.8%), and others in 15 patients (13.8%). In the pivot shift pattern group, anterior cruciate ligament (ACL), medial meniscus, and medial collateral ligament (MCL) injuries were most commonly seen in 94.8, 50, and 44.8% of patients, respectively. Among the clip pattern group, MCL, ACL, and medial meniscus injuries were most common in 90.9, 36.4, and 36.4%, respectively. Regarding the dashboard injury group, posterior cruciate ligament (PCL), ACL, and medial and lateral menisci were the most common injury structures (100, 57.1, 42.9, and 42.9%, respectively). Despite the hyperextension pattern being found in a small number of patients, it shows 100% medial meniscal and 66.7% PCL injuries. Within the group of lateral patellar dislocation patterns, 100% of cases exhibited injuries to the medial patellofemoral ligament.ConclusionsPrecise localization of the marrow contusion around the knee and defining its pattern help to anticipate the most probable associated soft tissue injuries and, thus, can increase our sensitivity in their detection. This can have a better impact on patients' management outcomes.

Stress effects on interaction modes and cross-slip annihilation distance of screw dislocation interactions

Phase field microelasticity model is used to study the cross-slip and annihilation of screw dislocations in face-centered cubic crystals, revealing the non-negligible effects of Escaig stress on dislocation interactions. We find that the Escaig stress (in the direction that expands the stacking fault width) promotes the partial dislocation interactions and the Fleischer cross-slip mechanism. In addition to three fundamental dislocation interaction modes, three new dislocation interaction modes emerge with the formation of parallel stacking fault bands. Furthermore, with the increasing of Escaig stress, the critical annihilation distance in dislocation interactions can be appropriately reduced. This research provides novel insights for manipulating strain hardening and understanding the formation of dislocation patterns.

Transradial Trans-Scaphoid Transcapitate Transtriquetral Perilunate Dislocation of the Wrist

Abstract Perilunate dislocation is a severe complex injury associated with carpal bone fracture. The most common pattern is trans-scaphoid perilunate dislocation. A transradial, trans-scaphoid, transcapitate, and transtriquetral perilunate dislocation pattern, an extremely rare complex injury of the wrist joint, may be the first reported case of a combination of three carpal bone fractures and radial styloid fracture associated with perilunate dislocation.

Mechanisms of electrically assisted deformation of an Al–Mg alloy (AA5083-H111): Portevin–Le Chatelier phenotype transformation, suppression, and prolonged necking

Aluminum-magnesium wrought alloys are well known for their advantageous properties and their application in various industries. However, the occurrence of the Portevin–Le Chatelier (PLC) effect leads to the formation of bands on the surface, thereby restricting the application of parts from Al–Mg alloys, primarily due to aesthetic concerns. Applying electrical pulses during deformation may not only improve the mechanical properties, moreover, it also affects the PLC effect. In this work, the properties of AA5083-H111 were investigated using standardized and electrically assisted tensile tests. Tensile behavior was assessed at room temperature, 250 °C, cryogenic conditions, and at two distinct electrically assisted conditions. We found that electrically assisted tensile testing leads to increased fracture strain compared to standard room temperature and cryogenic conditions. Furthermore, there was a transformation in PLC phenotypes, which included a partial suppression of the PLC effect. A spatio-temporal analysis of strain rate and strain highlights considerable differences in the occurrence of PLC bands and prolonged necking compared to standard room temperature testing. Furthermore, a modified dislocation pattern was observed using transmission electron microscopy.

Plate Fixation of Hamate Fractures in Fourth and Fifth Carpometacarpal Fracture Dislocations.

Traumatic dislocations of the fourth and fifth metacarpals, in conjunction with dorsal hamate fractures, are a common entity that can lead to the instability of the fourth and fifth carpometacarpal (CMC) joints. The fracture of the hamate, usually in a coronal dorsal shear configuration, can lead to the dorsal subluxation of the hamatometacarpal joint. Open reduction and internal fixation of the hamate bone with a dorsally applied buttress plate can re-establish a stable and congruent joint surface and anatomically align the articular surfaces of the small and ring finger CMC joints. We present a technique of internal fixation of the hamate to facilitate the reduction of the hamatometacarpal joints. Using a dorsal approach centered over the fourth and fifth CMC joints, the joint surfaces are directly visualized and subsequent fixation of the hamate is performed using a 1.3-mm T-plate to securely buttress its articular surface. This technique presents an approach to the multifaceted injury pattern of fourth and fifth CMC dislocations associated with a hamate fracture.

Phase division and recognition of crystal HRTEM images based on machine learning and deep learning

The High Resolution Transmission Electron Microscope (HRTEM) images provide valuable insights into the atomic microstructure, dislocation patterns, defects, and phase characteristics of materials. However, the current analysis and research of HRTEM images of crystal materials heavily rely on manual expertise, which is labor-intensive and susceptible to subjective errors. This study proposes a combined machine learning and deep learning approach to automatically partition the same phase regions in crystal HRTEM images. The entire image is traversed by a sliding window to compute the amplitude spectrum of the Fast Fourier Transform (FFT) in each window. The generated data is transformed into a 4-dimensional (4D) format. Principal component analysis (PCA) on this 4D data estimates the number of feature regions. Non-negative matrix factorization (NMF) then decomposes the data into a coefficient matrix representing feature region distribution, and a feature matrix corresponding to the FFT magnitude spectra. Phase recognition based on deep learning enables identifying the phase of each feature region, thereby achieving automatic segmentation and recognition of phase regions in HRTEM images of crystals. Experiments on zirconium and oxide nanoparticle HRTEM images demonstrate the proposed method achieve the consistency of manual analysis. Code and supplementary material are available at https://github.com/rememberBr/HRTEM2.

More severe surface relief but stronger fatigue resistance at small scales: Vacancy-assisted fatigue damage mechanism

Surface relief in forms of extrusions and intrusions as the substantial feature of early fatigue damage is one of the most important phenomena studied in metal fatigue. The most common surface relief models in bulk metals are agreed to be correlated with the formation of typical dislocation patterns as persistent slip bands (PSBs), while little is known about the fundamental mechanisms at submicron and even nanometer scales where dislocation pattern formation is fully inhibited. Here, as exampled with thin Au films, the underlying fatigue damage mechanism at small scales is investigated through the quantitative characterization of fatigue damages. Continuous generation and migration of vacancies is found to be crucial for the shape of extrusion/intrusions and kinetics of their growth at submicron and even nanometer scales. Due to the degraded dislocation interaction and intensified vacancy diffusion, the delayed vacancy accumulation in the small-scale metal interior suppresses the extrusion and interface void formation in thinner films, which finally leads to the superior ability to support tremendous surface relief and strong fatigue resistance. The finding of the vacancy-dominated fatigue mechanism at small scales extends our understanding of the metal fatigue mechanisms down to the submicron and even nanometer scales and suggests a novel interface engineering strategy by vacancy behavior modulation for fatigue-tolerance material design.

Contrasting the nature of plastic fluctuations in small-sized systems of BCC and FCC materials

It is now well established that, upon decreasing system sizes down to a few μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upmu$$\\end{document}m or below, the nature of plasticity of metallic materials is changing. Two important features of this small-sizes plasticity are two size effects, which can be summed up as “smaller is stronger” and “smaller is wilder”, this last observation meaning that the jerkiness of plastic deformation becomes prominent at small enough system sizes. In FCC and HCP materials, this is now rather well understood within the framework of obstacle-controlled plasticity, from the key role of a scaling ratio between the system size L and an internal scale l mainly dictated by dislocation patterning in pure materials, or by the nature of extrinsic disorder in alloys. The situation is more complex in BCC materials, for which screw dislocation motion becomes lattice-controlled, i.e. is thermally activated, below a transition temperature Ta\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_a$$\\end{document}. Therefore, in small-sized BCC systems, temperature, size and strain-rate effects combine to give rise to a complex landscape. We show, from an analysis of the literature as well as micropillar compression tests on Molybdenum performed with different sample sizes, under different temperatures and different applied strain-rates, that (i) near or above Ta\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_a$$\\end{document}, the plasticity of pure BCC metals is athermal and obstacle-controlled, much like at bulk scales, therefore mimicking that of pure FCC metals; (ii) below Ta\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_a$$\\end{document} and for sample sizes larger than ∼\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim$$\\end{document}1 μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upmu$$\\end{document}m, BCC plasticity becomes lattice-controlled, this damping dislocation avalanches and thus reducing wildness; but (iii) for very small systems, still below Ta\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_a$$\\end{document}, the role of screw dislocations on plasticity vanishes, i.e. is no more lattice-controlled, opening again the door for wild plastic fluctuations and jerkiness.

Demographics and Outcomes of Glenohumeral Dislocations in Individuals With Elevated Body Mass Index.

No specific study has investigated the characteristics and outcomes of anterior shoulder dislocations in morbidly obese individuals. The purpose of this study was to describe shoulder dislocations in patients with body mass index (BMI) greater than 40. A retrospective review was conducted to identify patients aged 18 years and older with a BMI ≥40 who presented with a shoulder dislocation in a single institution from 2000 to 2020. Dislocation patterns, associated injuries, treatment modalities, and associated complications were recorded. A significant increase was noted in the number of patients with BMI greater than 40 presenting per year (r2 = -0.831, P < 0.01) over the past 20 years. A significant increase was noted in the average BMI per year in this population (r2 = 0.504, P = 0.028). Fifteen patients (19.5%) experienced at least one recurrent dislocation episode. Ten patients had a Bankart lesion that was associated with an elevated BMI (P = 0.04). Nine patients (11.7%) sustained an associated neurologic injury (no association with BMI). Over time, there has been an increase in shoulder dislocations in morbidly obese individuals in the United States, alongside an overall increase in the average BMI of patients who present with shoulder dislocations.

3D microstructural and strain evolution during the early stages of tensile deformation

Dislocation patterning and self-organization during plastic deformation are associated with work hardening, but the exact mechanisms remain elusive. This is partly because studies of the structure and local strain during the initial stages of plastic deformation are a challenge. For this reason, literature data typically cover strains from 0.05-0.1 and higher. Here we use Dark Field X-ray Microscopy to generate 3D maps of embedded 350×900×72μm3 volumes within three pure Al single crystals. Tensile deformation was applied to true strains of 0.6%, 1.7%, and 3.5% along the [10 13 −10] direction. Orientation maps revealed the existence of two distinct types of planar dislocation boundaries both at 0.6% and 1.7% but no systematic patterning. At 3.5%, these boundaries have evolved into a well-defined checkerboard pattern, characteristic of Geometrically Necessary Boundaries, GNBs. The crystallographic alignment of the GNBs match that in polycrystals for grains of similar orientation. The GNB spacing measured perpendicular to the planesis ≈6μm and the misorientation ≈0.2°, in fair agreement with literature data for higher strains. By contrast to the sharp boundaries observed at higher strains, the boundaries are associated with a sinusoidal orientation gradient, showing that they are not yet fully formed. Maps of the elastic strain along the (111) direction exhibit strain variations of ±0.0002 with an average domain size of 3μm.

Substitutional and interstitial atoms co-doping overcomes the strength–ductility trade-off in lightweight refractory medium-entropy alloys

Interstitial or substitutional solid solution strengthening is a common method for enhancing material mechanical properties, however, it is unclear whether their synergy can lead to better mechanical properties in materials. Here, we have demonstrated that the synergy of interstitial and substitutional elements can overcome the strength-ductility trade-off, which was substantiated in an O and Al co-doping (TiZrNb)94.5O0.5Al5 (O0.5Al5) lightweight refractory medium-entropy alloy (LRMEA) with a density ∼6.0 g/cm3. The co-doping LRMEA exhibits a simultaneous enhancement in strength and ductility with a yield strength of ∼1025 MPa and a fracture elongation of ∼35%, compared with the O or Al single doped alloys, i.e. (TiZrNb)99.5O0.5 (O0.5) and (TiZrNb)95Al5 (Al5). This combined increase in strength and ductility was attributed to synergistic interstitial and substitutional solid solution strengthening and the modification of dislocation motion mode from planar slip delocalization to a relatively diffuse, three-dimensional dislocation pattern, effectively alleviating stress concentration. This work provides valuable insight into the development of high-performance lightweight alloys.

Epidemiology of Shoulder Dislocation Treated at Emergency Departments in the United States Between 1997 and 2021.

The exact incidence of shoulder dislocation in the general population of the United States (US) has yet to be well studied. To establish the current incidence and patterns of shoulder dislocations in the US, especially regarding sports-related activity. Descriptive epidemiology study. This was a retrospective analysis of shoulder dislocations encountered in emergency departments in the US between 1997 and 2021 as recorded in the National Electronic Injury Surveillance System (NEISS). Data were further analyzed according to patient age, sex, and sports participation. Information from the United States Census Bureau was used to determine the overall incidence of dislocations. A total of 46,855 shoulder dislocations were identified in the NEISS database, representing a national estimate of 1,915,975 dislocations (mean 25.2 per 100,000 person-years). The mean patient age was 35.3 years. More than half of the dislocations (52.5%) were sports-related, and basketball (16.4%), American football (15.6%), and cycling (9%) were the sports most commonly associated with dislocation. Most dislocations (72.1%) occurred in men. This disparity by sex was more significant for sports-related dislocations (86.1% in men) than nonsports-related dislocations (56.7% in men; P < .001). With sports-related dislocations, people <21 years experienced a significantly higher proportion versus those >39 years (44.6% vs 14.9%; P < .001), while the opposite distribution was seen with nonsports-related dislocations (<21 years: 12% vs >39 years: 51.7%; P < .001). Women outnumbered men with shoulder dislocation among people >61 years. Sports-related shoulder dislocations were more common among younger and male individuals than older and female individuals. Contact sports such as basketball and American football were associated with more shoulder dislocations compared with noncontact sports.

Characterization of dislocations induced by Vickers indentation in GaN for explaining size ratios of dislocation patterns

Characterization of dislocations induced by Vickers indentation in GaN for explaining size ratios of dislocation patterns

Influence of build direction on the ratchetting-fatigue interaction of heat-treated additively manufactured 316L stainless steel

This study has investigated the cyclic deformation and ratchetting-fatigue interaction of 316L stainless steel fabricated by laser powder bed fusion (LPBF) and subjected to a 900 °C/2 h post-heat treatment, considering both the vertical and horizontal orientations. Strain- and stress-controlled low cycle fatigue (LCF) tests are conducted to explore the cyclic deformation and the effects of the mean stress and stress amplitude on the fatigue life and ratchetting deformation. A detailed analysis of the cyclic deformation mechanism is conducted through X-ray microtomography and transmission electron microscope (TEM) observations. The results show that post-heat treated LPBF 316L steel exhibits cyclic hardening followed by a non-saturated cyclic softening stage. This behavior is attributed to the evolution of dislocation density and dislocation patterns, and the formation of surface cracks. The ratchetting strain and its rate are sensitive to the mean stress and stress amplitude. The fatigue lives of vertically built specimens are slightly higher under strain-controlled loading conditions, but significantly lower under stress-controlled loading conditions than those of horizontally built ones. Furthermore, ratchetting deformation can promote fatigue damage, resulting in a reduction in fatigue life.